Here I am presenting both the statistics as well as the known major causes of liver cancer.
Statistics
In the US liver cancer occurs relatively infrequently when compared to the rest of the world.
There are about 10 new cases per 100,000 people in the US per year, 7 per 100,000 people are males and 3 are females. Here are some other countries for comparison (modified from Ref. 1, page 885). As it can be seen on this table, in Mozambique liver cancer is 16-fold more common and in China about 5-fold more common than in the US.
On the other hand Brazil and Germany have lower rates than the US. Women always have 2 to 3 times lower liver cancer rates around the world, which is something that has not yet been explained.
Annual new cases of liver cancer in various countries
| Country: | Males: | Females: |
| (persons per 100,000) | ||
| United States | 7 | 3 |
| South East Africa (Mozambique) | 113 | 31 |
| Brazil (Sao Paulo) | 4 | 3 |
| Korea | 14 | 3 |
| Japan | 7 | 2 |
| China (Shanghai) | 34 | 12 |
| Germany (Hamburg) | 5 | 2 |
The death rate in the US for males is about 2 deaths per 100,000 people, which shows that more than half survive. This is largely so because of the improved surgical therapy involving either early partial resection of the affected liver or early liver transplantation.
Causes
Apart from carcinogens, which attack the liver cells directly, there are two other major causes: viral hepatitis and cirrhosis of the liver. Hepatitis B and C are the most common causes in countries with a high rate of liver cancer. It can be linked to unhygienic conditions such as contaminated water (mainly endemic hepatitis B). Life styles of prostitutes and unsterile injection techniques in the drug scene play a major role in the transmission of hepatitis C. Chronic inflammation of viral hepatitis leads to cirrhosis of the liver and a high percentage of people with cirrhosis develop liver cancer.
It has been determined that the high rate of liver cancer in Asia or Africa is linked to endemic hepatitis B and contamination of food with mycotoxins, which is found in stored grains, swirled up dust from soil as well as unpurified drinking water. Researchers found that Chinese who migrate from China to Hawaii will have a low liver cancer rate within 1 or 2 generations. Conversely, Jews who are born in Israel have half the rate than those who are born in Europe, Asia or Africa. (Ref.1, p.886). These type of studies help to identify if a disease is caused by genetic factors or the environment. The major factor with liver cancer is the environment and people’s life style.
References:
1. Cancer: Principles &Practice of Oncology.4th edition. Edited by Vincent T. DeVita, Jr. et al. Lippincott, Philadelphia,PA, 1993. Chapter on Hepatobiliary Neoplasms.
2. Cancer: Principles&Practice of Oncology. 5th edition, volume 1. Edited by Vincent T. DeVita, Jr. et al. Lippincott-Raven Publ., Philadelphia,PA, 1997. Chapter on Hepatobiliary Neoplasms.
3. SA Hussain et al. Ann Oncol 2001 Feb;12(2):161-172.
4. M Nakamura et al. J Cell Physiol 2001 Jun;187(3):392-401.
5. Conn’s Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier
6. Ferri: Ferri’s Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc
